Java program to find Determinant of a Matrix

Write a Java program to find the Determinant of a 2 * 2 Matrix and 3 * 3 Matrix. The mathematical formula to find this Matrix determinant is as shown below.

Java program to find Determinant of a 2 * 2 Matrix

It is an example to find the Determinant of a 2 * 2 Matrix. This code allows user to enter the values of 2 * 2 Matrix using the For loop. Next, we used the mathematical formula to find the matrix determinant.

import java.util.Scanner;

public class DeterminantOfMatrix {
	private static Scanner sc;
	
	public static void main(String[] args) {
		int[][] arr = new int[2][2];
		
		int i, j, determinant = 0;
		
		sc= new Scanner(System.in);
		
		System.out.println("\n Please Enter the Matrix Items :  ");
		for(i = 0; i < 2; i++) {
			for(j = 0; j < 2; j++) {
				arr[i][j] = sc.nextInt();
			}		
		}
		
		determinant = (arr[0][0] * arr[1][1]) - (arr[0][1] * arr[1][0]);

		System.out.println("The Determinant of 2 * 2 Matrix = " + determinant );
		
	}
}

Java 3 * 3 Matrix Determinant

This Java code finds the determinant of a 3 * 3 matrix. So, this Java example allows the users to enter the 3 * 3 matrix items. Please refer to C example to find Determinant article to understand this determinant code’s analysis in iteration wise.

import java.util.Scanner;

public class DeterminantOfMatrix {
	private static Scanner sc;
	
	public static void main(String[] args) {
		int[][] arr = new int[3][3];
		
		int i, j, x, y, z, determinant = 0;
		
		sc= new Scanner(System.in);
		
		System.out.println("\n Please Enter the Matrix Items :  ");
		for(i = 0; i < 3; i++) {
			for(j = 0; j < 3; j++) {
				arr[i][j] = sc.nextInt();
			}		
		}
		
		x = (arr[1][1] * arr[2][2]) - (arr[2][1] * arr[1][2]);
		y = (arr[1][0] * arr[2][2]) - (arr[2][0] * arr[1][2]);
		z = (arr[1][0] * arr[2][1]) - (arr[2][0] * arr[1][1]);
		
		determinant = (arr[0][0] * x)- (arr[0][1] * y) + (arr[0][2] * z);

		System.out.println("The Determinant of 3 * 3 Matrix = " + determinant );
		
	}
}

Matrix Determinant output

 Please Enter the Matrix Items :  
10 20 30
40 50 60
70 80 90
The Determinant of 3 * 3 Matrix = 0